<html>
<head>
</head>


<body>
	<input id="number1" type="text">
	<input id="number2" type="text">
	<span id="result"></span>
	<button id="addbtn">xx</button>

	<script>
		function $(id) {
			return document.getElementById(id);
		}
		function add() {
			$("result").innerHTML = $("number1").value + $("number2").value;
		}
		$("addbtn").addEventListener("click", add);
	</script>
	<script src="1.js"></script>
</body>
</html>